Typewriting machine



Apr;1 28, 1931- A. E. OSWALD I 1,802,391

TYPEWR ITING MACHINE Filed July 15, 1926 4 Sheets-Sheet l In ven for:

Aria/nay April 28, 1931- A. E. OSWALD 1,802,391

TYPEWRITING MACHINE Filed July 15; 1926 4 Sheets-Sheet 2 lm/emor:

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Afro/we April 28, 1931. A. E. 'OSWALD TYPEWRITING MACHINE Filed July 15,1926 4 Sheets-Sheet 3 In vemor':

Afro/we April 28, 1931. A. E. OSW ALD TYPEWRITING MACHINE Filed July 15,1926 4 Sheets-Sheet 4 Hfforney Patented Apr. 28, 1931 UNITED STATESPATENT OFFICE ALFRED E. OSWALD, 0F EACKENSACK, NEW JERSEY, ASSIGNOR TOUNDERWOOD EL- LIOTT FISHER COMPANY, OF NEW YORK, N. Y., A CORPORATION OFDELAWARE TYPEWRITING MACHINE Application filed July 15,

This invention relates to mechanically operated typewriting machines inwhich the keys are depressed part way to set the typebar drivingmechanism.

It has been proposed to operate the typebars by means of a complicatedcam-mechanism.

It is one of the objects of this invention to simplify the driving ofthe type-bar. There is provided a continuously revolving shaft of ironor the like, which is surrounded by an electromagnetic coil'throughwhich an electric current is caused to flow. The shaft protrudes at bothends of the coil and co-operates with a U-shaped armature straddling thecoil and contacting with the shaft. The armature is mounted on a slidingmember which carries a cross-bar designed to engage a pawl operativelyconnected to each type-bar, and uponoperation of a type-key the pawl isthrown in the path of the slide which picks it up and swings thetype-bar. The depression of a key is also effective to close an electriccircuit through the coil in a manner to magnetize the shaft and toconsequently generate a magnetic fiow through the shaft which attractsthe armature and rolls it on the shaft. This, of course, will move theslide upon which the armature is mounted and the type-key which has beenpartly depressed will be automatically swung to its typing position.When the slide reaches the end of its travel, the electric circuitthrough the coil is interrupted and the slide is returned to its normalposition by means of a spring. The magnetic flux between the magnetizedrevolving shaft and its associated armature is great and although theattraction, and consequent friction of the two members, is constant, thedriving power of the shaft may be increased by increasing its speed. Thespeed may also be controlled to determine the force of the type blowsagainst the platen.

' It will be understood that owing to the peculiar construction of theUnderwood type- 1926. Serial No. 122,537.

action the key-depression is very light at the beginning of the strokeand increases gradually as the key is further depressed. In thisinvention advantage is taken of this condition. The first portion of thekey depression is used to set the driving mechanism, which issubsequently effective to completely swing the type-bar associated withthe key.

According to one feature of the invention,

means are provided to limit the depression of the keys to thereb improvetheir touch by preventing the col apsing of the keys under the fingers.To this end there is provided a special keyboard overlying the regularkeydepressing the type-keys, which are picked by I the driving mechanismafter being partly depressed.

Another feature of this invention relates to means for rendering thetypewriting machine manually operable. when the electric power is cutoff. To this end there is provided a depressible button which moves theoperating slide to ineifective position. The machine may be removed fromits driving mechanism in case it is desired to operate it by hand whilethe electric power is cut ofi'.

This invention may be used in connection with typewriting machineshaving a carriagereturn mechanism of the type disclosed in the patent toHenry LQPitman, No. 1,580,326, dated April 13, 1926. However, since itis desired to rotate the electric motor continuously to drive thetype-keys, the starting switch with which the carriage-return mechanismis usually provided is eliminated, and

the motor lead wires are connected to terminal blocks in the drivingmechanism.

The slide which operates the type-bars is mechanically returned to itsnormal position by means of a spring. In'case of accidental misuse ofthe machine the slide may not reach the end of its travel in which casethe circuit would remain closed and the parts would be strained. In thisinvention means are provided whereby the circuit may be opened bydepressing a button to thus permit the slidereturning spring to actuateand to normalize the machine.

Owing to the enormous scale in which typewriting machines are made, evenslight changes in the design of simple parts are costly because theyalways involve the discarding and building of tooling equipment. In viewof this it is considered an important feature of this invention that astandard machine may be taken out of stock and transformed into anelectric typewriter by simply attachin a few clamps to the type-keys.Thus, old machines be electrically driven by simply purchasing aninexpensive base into which the driving mechanism is built.

Other features and advantages will hereinafter appear.

In the accompanying drawings,

Figure 1 is a cross-sectional view, in eleva-' tion, of an Underwoodtypewriting machine having the automatic type-key-driving mechanismapplied thereto.

Figure 2 is a cross-sectional view through line 22 of Figure Figure 3 isa plan View of the driving mechanism with the machine removed.

Figure 4 is a cross-sectional view through line 4-4 of Figure 1, showingthe back of the typewriter and the carriage-return mechamsm.

Figure 5 is a cross-sectional view through line 5-5 of Figure 3.

Figure 6 is a cross-sectional view through line 6-6 of Figure 3.

Figure 7 shows one form of the invention in which a clamp is providedfor utilizing a standard key-lever.

Figure 8 is a detail cross-sectional view, showing a brush contactingwith the rotating driving shaft.

Figure 9 is an operating view, showing one of the key-levers partlydepressed, the temporary switch being closed.

Figure 10 is an operating view, showing a type-bar partly swung by theaction of the driving mechanism.

Figure 11 shows one form of the invention in which a special keyboard isprovided to limit the depression of the keys.

Figure 12 is a diagrammatic view, showing the electrical connections.

The Underwood typewriting machine is provided with a traveling carriage20, upon which a platen 21 isrotatably mounted. The

carriage is slidably mounted on rails 22 and 23, and its travelingmovement is controlled by means of escapement-mechanism 24. Theescapement-mechanism is operated by a universal bar 25, which is struckby type-bars 26 operatively connected to depressible keys 27. The keysare mounted at the ends of levers 28 pivotally mounted on a shaft 29 andoperate a bell-crank 30, which swings the typebars.

Owing to the peculiar construction of this type-action, thekey-depression is very light at the beginning of the stroke, but itgradually becomes harder as the key is further depressed. It is one ofthe objects of this invention to mechanically operate the type-barsduring the time when the depression of the keys is harder. To this end,each type-bar is provided with a bell-crank 31 pivotally mounted on across-shaft 32, which is fast to the frame of the machine 33 by. meansof screws 34. One end of the bell-crank is provided with an elongatedslot 35, which engages a pin 36 carried by the lever 28. The lower armof the bell-crank 31 extends downwardly and carries at the end thereof apawi 37 fast to a stud 38 pivotally mounted on the arm. Said pawl isnormally held in the position shown in Figure 1 by means of a spring 39.It will be understood that there is one bell-crank for each key, asshown in Figure 2.

The key-driving mechanism is mounted on a base 40 under the typewriterand includes a slide 11 mounted on supporting studs 42 and 43 fast tothe base 40. The slide is held in place by means'of screws 4: 1 andcarries a cross-plate 45 fast to the slide by means of rivets 46. Thecross-plate extends the full width of the machine, the forward endthereof being bent upwardly to form a ledge or hook 47. The slide isheld in its normal position, as shown in Figure 1, by means of a spring48 mounted on a spring-stud 49 and fast to the end of the slide.

In order that the slide 41 may be automatically reciprocated upondepression of any one of the keys, there is provided a rotating shaft 50made of magnetizable material, such as'soft iron, supported on insulatedbrackets 51. The rotating movement is imparted to the shaft by means ofan electric motor 52 and a driving mechanism including pulley 53 and 54,and a belt 55., The pulley 54 is fast to the shaft by means of a screw56, while the pulley 53 is mounted on a motor shaft 57. The shaft 50 issurrounded with anelectromagnetic coil 58mounted onthe base by means ofend brackets 59 and screws 60. This coil is effective to magnetize theshaft when an electric current is caused to flow therethrough.

The operating connection between the rotating shaft 50 and the slidedlincludes a plate 61 slidably mounted on the slide 41 and held in itsnormal position by means of a spring 62 mounted between spring-studs 63and 64. The spring-stud 63 has a flange which serves as means forguiding the sliding plate 61 and cooperates with another stud 65,

which is slidably mounted on the slide 41. The end of the plate 61 isprovided with a bracket 66 fast thereto by means of a screw 67surrounded with insulating material 68,

ture is held in the position shown in Figure 1 by gravity, and issupported by pins 71 fast to the brackets 59. It will be noted thatthere is a gap between the shaft and the armature, so that when theshaft is rotating the armature is not affected by its rotation until theshaft is magnetized. The armature is of U-shaped construction andstraddles the coil 58 so as to contact with the shaft at both sides ofthe coil, thus providing for a maxifn'um magnetic flow and a maximumadherence of the armature to the shaft.

Each key-lever is depressed in a manner to swing the bell-crank 31 sothat the rear end 72 of the pawl 37 will strike a bail-,piece 73pivotally mounted on a stud 75 carried by bent ends 74 of thecross-plate 45. The bent ends slide on the base and serve as a means forlaterally positioning the slide 41. Said bailpiece is held in theposition shown in Figure 1 by means of springs 76 carried by studs 77and 78. These springs are stronger than the spring 39, and, for thisreason, upon swinging the bell-crank 31, the pawl 37 will be swung tothe position shown in Figure 9. However, upon swinging the bell-crank 31further, the tension of thespring 7 6 will be overcome, thereby swingingthe bail-piece 73 to the position shown in Figure 9. The bail-piece iseffective to close a switch 79, which temporarily magnetizes the shaft50 by closing an electric circuit through terminals 80, 81 and 82, thecoil 58 and the terminals 83 and 84. The current also flows through aswitch 85, the construction and purpose of which will be explainedlater.

The flow of current through the circuit just described, and shown inFigure 12, is effective to magnetize the shaft 50 which attracts thearmature 70 as shown in Figure 10. When the armature is attracted by theshaft a magnetic circuit is closed which flows through the armature andthrough the shaft. This powerful attraction between the shaft and thearmature is effective to roll the armature on the shaft, thereby movingthe operating slide 41 rearwardly, as indicated by the arrow in Figure10, but since thepawl 37 has been swung in the path of the slide 41, thepawl will be picked up by the slide in a manner to swing the bell-crank31, and thereby complete the depression of the typekey 27 associatedwith the bell-crank.

After the slide 41 reaches the end of its travel it is necessary tointerrupt the circuit so as to permit the spring 48 to retract the slideto its normal position. In order to facilitate the breaking of thiscircuit, it is proposed to short circuit the current as indicated bydotted lines 86 in Figure 12, when the armature contacts with the shaft50, which in turn contacts with a brush 87 at the top thereof. Saidbrush is mounted on a block 88 of insulating material, which is securedto the base 40 by means of a screw 89, and serves also as aterminal-block for the negative side of the main and motor circuit. Itwill be understood from the foregoing that when the armature isattracted by the shaft, the current does not flow through the terminal80, but through the brush 87, the shaft 50, the armature 70, through thecoil 58 which is connected to the armature by means of a screw 90, andout of the coil through terminal 83, switch 85, and terminal 84.Immediately after the slide 41 starts moving, the switch 79 is opened bythe action of the spiing 76. It is then only necessary to interrupt thelast-mentioned circuit in order to demagnetize the shaft 50, and topermit the actuation of the spring 48. To this end there is provided aplate 91 of insulating material which overlies the armature 70 andinterposes the shaft and the armature when the latter reaches the end ofits travel, to thereby interrupt the electrical connection between theshaft and the armature. In order to pro tect the wearing surface of theplate 91, which is of soft material, there may be provided an overlyingplate 92 of sheet-metal. plates are fast to the armature by means ofscrews 93.

The switch 85 serves as a means for holding the main line normallyclosed, and for facilitating the manual temporary interruption of thecurrent in case the type-bars or any part of the mechanism gets jammed.The switch, which is fully illustrated in Figure 3, is mounted on ablock of insulating material 94, fast to the base by means of screws 95.One end of the terminal 84 is fastened to the block by means of a screw96 and a Both nut 97. The head of the screw 96 contacts 1 key. Thespring 98 is bent rearwardly to the position shown in dot-and-dash linesin Figure 3. The movement of the bar 103 is limited by means of a pin104 and two prongs 105 forming an integral part of the bar. The otherend of the bar is fitted in a slot in the block and is held in place bythe head of one the screws 95.

One of the advantages of this invention is 3 that the machine may bemanually operated, when desired, in case the electrical power is cutoff. To this end means are provided whereby the operating slide 41 maybe moved rearwardly so as to permit the unobstructed swinging movementof the bell-crank 31. The

slide may be moved by means of a key 106, mounted at the end of a link107, which is connected by means of a pin 108 to an arm 109 pivotallymounted on a shoulder-screw 110 fast to the base as shown in Figure 6.The end of the arm 109 is operatively connected to operate the slide bymeans of a stud 111. The link 107 may be latched in its operatedposition by engaging a notch 112 against the edge 113 of a slot in thebase through which the link protrudes to the outside of the casing.

The power required for driving the shaft 50 is supplied by the electricmotor 52 which serves also as the motive power for returning thecarriage. The end of the motor-shaft 57 carries a worm 114 which engageswith a worm-gear 115 fast to a shaft 116 journaled on a supportingbracket 117. The inner end of the shaft 116 carries a gear 118 whichengages with a rack 110 mounted on the carriage 20. The gear 118 isslidably mounted on the shaft 116 and may be moved into engagement withteeth 120 of a clutch-member 121, said clutch-member being fast to theshaft 116. The means for sliding the gear 118 is not shown in thisinvention, but is fully illustrated in said patent to Pitman.

The switch indicated generally by the numeral 79 serves as a means fortemporarily closing the circuit through the coil 58 so as to magnetizethe shaft 50 which attracts the armature and closes the main circuit. Itwill be understood that a switch of any approved design could be usedfor this purpose. In the design adopted, there is provided a pair ofblocks of insulating material 122 upon which spring-leaves 123 aremounted by means of screws 124 and nuts 125. The screws are insulatedfrom the slide 41 by means of washers 126. Each leaf carries, at the endthereof, contact points 12 Tthrough which the current passes when thetwo contact points are short circuited by means of a metal-plate 128which may be provided with contact points 129 to eliminate sparking.Said plate 128 is carried by the bail-piece 73 to which it is secured bymeans of screws 130 and an intervening plate 131 of insulating material.

In order that a standard typewriting machine of the Underwood type maybe utilized in connection with this invention, there may be provided aseries of clamps of the type illustrated in Figure 7. Said clamps aresecured to the key-levers 28 in a position such as shown in dot-and-dashlines in Figure 1 by means of a shoulder-screw 132 which takes the placeof the pin 36 shown fast to the keylever of special construction. Thescrew 132 is also effective to hold a bracket 133 in place by means of abrace 134 which receives the screw 132.

The key-depression may be limited when desired by means of a specialkeyboard shown in Figure 11. The keyboard is provided with keys 135having stems slidably mounted in holes in a frame consisting of an upperplate 136 and a lower plate 137, both plates being held together bymeans of rivets 138. The frame is fitted to the machine-frame and theends 139 of the key-stems are upset or enlarged to prevent accidentaldisplacement of the keys. In order to prevent clicking of the specialkeys, there may be provided felt Washers 140 which limit thekey-depression. It will be understood that the machine is operablewithout the special keyboard, but then the depression of the regularkeys is not limited.

The motor 50 is provided with leads 141 and 142, which are secured tothe terminalblocks 88 by means of screws 143. Supply leads 144 and 145are also secured to the terminal-blocks by means of the screws 143. Themain line may be provided with a snapswitch 146 to cut off the current.This switch may be secured to the machine near the keyboard tofacilitate its operation.

. Variations may be resorted to within the scope of the invention, andportions of the improvements may be used without others.

Having thus described my invention, I claim:

1. A power-driven typewriting machine including type-bars, depressibletype-keys associated with the type-bars, and means for automaticallycompleting the depression of the keys, to thereby operate the type-barsafter the keys have been partly depressed, said means including acontinuously revolving shaft, means controlled by the keys to magnetizesaid shaft, and an armature c0- operating with the shaft, said armaturebeing operatively connected with the partlydepressed key in a manner toswing the typebar associated with the depressed key.

2. An automatic typewriting machine including, in combination,type-bars, depressible type-keys therefor, key-driving mechanism, andmeans controlled during the first part of the key-depression for settingthe driving mechanism, said key-driving mechanism including an operatingslide, means for operatively connecting the slidewiththepartly-depressed key, and means for reciprocating the slide, saidlast-mentioned means including a spring for holding the slidiin itsnormal position, an armature pivotally mounted on the slide, a revolvingmagnetizable shaft co-operating with said armature, means, controlled bythe key being depressed, for closing an electrical circuit effective tomagnetize said shaft, the shaft being effective to attract the armatureand to roll it thereon to thereby draw on the operating slide, and meansfor interrupting the flow of current, to thereby demagnetize the shaftand to permit retracting movement of the operating slide.

3. In a typewriting machine having typebars and depressible keystherefor, means controlledduring the first portion of the keydepressionfor automatically completing the depression of the key, said meansincluding a bell-crank operatively connected with each key, a pawlcarried by each bell-crank, a sliding member, a source of power, andmeans for swinging the pawl associated with the bell-crank in the pathof the sliding member, said last-mentioned means being also effective toconnect the sliding member with the source of power.

4. The combination of means forautomatically driving the keys andtype-bars of a typewriting machine, said means including, incombination, an operating slide, a revolving shaft, an electromagneticcoil surrounding the shaft, the latter protruding at the ends of thecoil, an armature carried by the slide, said armature straddling thecoil and being normally held in close proximity'to the v shaft, andmeans for selectively connecting the keys with the slideand for causingthe coil to magnetize the shaft in a manner to attract the armature andto roll it thereon, to thereby move the slide therewith.

5. The combination with a typewriting machine having a travelingcarriage, typebars, and type-keys therefor, of a continuously runningmotor, mechanism operatively connected to the motor for returning thecarriage, and electromagnetic means co-operative with said motor toautomatically drive the type-bars upon partly depressing the type-keys.

6. In a typewriting machine having typebars and depressible keystherefor, means controlled during the first portion of the keydepressionfor automatically completing the depression of the key, said meansincluding a bell-crank operatively connected with each key, a pawlcarried by each bell-crank, a sliding member, a source of power, arevolving shaft of magnetic material running on insulated bearings, anelectromagnetic coil surrounding the shaft, a by-pass armature ofmagnetic material for closing a magnetic circuit through the shaft andthe armature, said armature being pivotally mounted on said slidingmember, and means for swinging the pawl associated with the bell-crankin the path of the sliding member, said lastmentioned means being alsoeffective to initiate a flow of electrical current through the coil.

7 A power-driven mechanism for the type-bars of a typewriting machineincluding, in combination, an operating slide, an armature of magneticmaterial carried by said slide, a revolving shaft of magnetic material,co-operating with said armature to roll it on the shaft, means formagnetizing said shaft during the first portion of the key-depression,and means for moving an interposing member in the path of the slideduring the first portion of the key-depression, said interposing memberbeing effective to swing the type-bar associated with thepartly-depressed key upon operation of the slide.

8. A power-driven mechanism for the typebars .of a typewriting machineincluding, in combination, an operating slide, an armature of magneticmaterial carried by said slide, a revolving shaft of magnetic material,co-operating with said armature to roll it on the shaft, means formagnetizing said shaft during the first portion of the key-depression,means for moving an interposing member in the path of the slide duringthe first portion of the key-depression, said interposing member beingeffective. to swing the type-bar associated with the partly-depressedkey upon operation of the slide, means controlled by the slide forcausing the shaft to be demagnetized in a manner to permit retractingmovement of the slide, and a spring to retract the slide to normalposition.

9. A power-driven mechanism for the type-bars of a typewriting machineincluding, in combination, an operating slide, an armature of magneticmaterial carried by said slide, a revolving shaft of magnetic material,co-operating with said armature to roll it on the shaft, means formagnetizing said shaft during the first portion of the key-depression,means for moving an interposing member in the path of the slide duringthe first portion of the keydepression, said interposing member beingeffective to swing the type-bar associated with the partly-depressed keyupon operation of the slide, means controlled by the slide for causingthe shaft to be demagnetized in a manner to permit retracting movementof the slide, and means for returning the slide to its normal position.

10. A power-driven mechanism for a typewriting machine having type-barsand keylevers therefor, said mechanism including, in combination, anoperating slide having a keylever-driving cross-bar, an interposingmember vibrated by each key-lever into the path of the slide during thefirst portion of a keydepression, and means for conveying motion to theslide, said means including a revolving shaft, an armature adjacent theshaft but levers therefor, said mechanism including, in combination, anoperating slide having a keylever-driving cross-bar, an interposingmember movable by each key-lever into the path of the slide during thefirst portion of a key depression, means for conveying motion to 'theslide, said meansincludmg a revolving shaft, an armature adjacent theshaft but spaced therefrom, an electromagnetic coil surrounding theshaft," a source of electric power, and a switch for temporarily closingan electrical circuit through the coil, said switch being closed by anyone of the keys during the first portion of their, depression, and meansfor short circuiting the current through the shaft and through thearmature when the latter is attracted by the'shart.

12. A power-driven mechanism for a typewriting machine having type-barsand keylevers therefor, said mechanism including, in

' combination, an operating slide having a keylever-driving cross-bar,an interposing member movable by each key-lever mto the Path of theslide during the first portion of the key-' depression, means forconveying motion to the slide, said means including a revolving shaft,an armature adjacent the shaft but spaced therefrom, an electromagneticcoil surrounding the shaft, a source of electric power, and a switch fortemporarily closing an electrical circuit through the coil, said switchbeing closed by any one of the keys during the first portion of theirdepression, and means for short circuiting the current through theshaftand through the armature when the latter is attracted by the shaft, saidlast-mentioned means including a terminalblock, and a brush carried bythe terminalblock and contacting with the shaft-x 13. Apower-driveirmechanism for a type- "writing machine having type-bars andkeylevers therefor, said mechanism including, in combination, anoperating slide, an interposing member movable by each key-lever intothe aath of the of tlie key-depression, means for conveying motion tothe slide to drive the key-levers,

- said means including a revolving shaft, an

armature adjacent the shaft but spaced therefrom, an electromagneticcoil surrounding the shaft, a'source of electric power for exciting thecoil, and a switch for temporarily closing an electrical circuitthrough; the coil, said switch being closed by any one of the keysduring the first portion of their depression, means for short circuitingthe current through the shaft and through the armature when thelatter'is attracted by the shaft, and

means for "automatically interrupting the determined position.

14. A power-driven mechanism for a type writing machine having type-barsand keylevers therefor, said mechanism including, in combination, anoperating slide, in interposing member movable by each key-lever intothe path of the slide during the first portion of the key-depression,means for conveying motion to the slide, to drive the key-levers, saidmeans'including a revolving shaft, an armature adjacent the shaft butspaced therefrom, an electromagnetic coil surrounding the shaft, :1source of electric power, and a switch for temporarily closing anelectrical circuit'through the coil, said switch being closed by any oneof the keys during the first portion of their depression, means forshort circuiting the current t'hroughthe shaft and through the armaturewhen the latter is attracted by the shaft, and means for automaticallyinterrupting the electrical circuit when the slide reaches apredetermined position, said last-mentioned means including a thin plateof insulating material movable with the armature to become effective toseparate the armature from the shaft.

15. A typekey-driving mechanism for a typewriting machine havingtype-bars and type-keys therefor, said mechanism including, incombination'a bell-crank associated with each key, a pawl carried byeach bellcranl an ol'ieratingslide having a ledge arranged to engage thepawl carried by the depressed key only, a normally open switch, abail-piece operable by any one of the pawls upon'operation of itsassociated bell-cranli to close the switch, and an electromagnet whosecircuit is controlled by said switch, said magnet including a revolvingshaft operable to attract said slide upon closingof said switch and movethe same to cause it to engage the pawl thrown in its path'by thepartly-depressed key in a manner to complete the depression of the keyand the swinging ofits associated type-bar to type.

16. A type-key-driving mechanism for a typewriting machine havingtype-bars and ing, in combination, a bell-crank associated Slide duringthe first POI'tiOII with each key, a pawl carried by each bell-r crank,an operating slide having a ledge arranged to engage the pawl carried bythe depressed key only, a bail-piece operable by any one of thebell-cranks upon operation of itsiassociated key, said bail-piece beingcarried by the slide, a normally open switchhaving one terminal on saidbail-piece and closable, upon swinging the bell-crank, to move thebail-piece, and means, controlled by said switch, for driving the slideto thereby cause the complete depression of the partly-depressed key andits associated type-bar.

17. A type -key-driving mechanism for it ewritin machine havin t )e-b delectrical clrcuitswhen the slide reachesapreyp g b yl an type-keystherefor, said mechanism including, in combination, a bell-crankassociated with each key, a pawl carried by each bellcrank, an operatingslide having a ledge arranged to engage the pawl carried by the de'ressed key only, a bail-piece operable by any one of the bell-cranksupon operation of its associated key, said bail-piece being carried bythe slide, a normally open switch having one terminal on said bail-pieceand closable upon swinging the bell-crank, to move the bail-piece,means, controlled by said switch, for driving the slide to thereby causethe complete depression of the partly-depressed key and its associatedtype-bar, said means including a revolving iron shaft, an iron armatureassociated with the shaft, said armature being pivotally mounted on theslide and being in close proximity to the shaft, and an electromagneticcoil surrounding the shaft, the electrical circuit being closed throughthe coil and the switch to magnetize the shaft and its associatedarmature, and means for restoring said slide to normal position.

18. A type-key-driving mechanism for a typewriting machine havingtype-bars and type-keys therefor, said mechanism including, incombination, a bell crank associated with each key, a pawl carried byeach bellcrank, an operating slide having a ledge arranged to engage thepawl carried by the depressed key only, a bail-piece operable by any oneof the bell-cranks upon operation of its associated keys, saidbail-piece being carried by the slide, a normally open switch having oneterminal on said bail-piece and closable, upon swinging the bell, tomove said bailpiece means, controlled by said switch, for driving theslide to thereby cause the complete depression of the partly-depressedkey and its associated type-bar, said means including a revolving ironshaft, an iron armature associated with the shaft, said armature beingpivotally mounted on the slide and being in close proximity to theshaft, and an electromagnetic coil surrounding the shaft, the electricalcircuit being closed through the coil and the switch to magnetize theshaft and its associated armature, means for interrupting the electricalcircuit when the slide which is rolled on the shaft reaches apredetermined position, and means for restoring the slide to its normalposition.

19. In a typewniting machine having type-bars, depressible type-keysassociated with said type-bars, and depressible keylevers connected tosaid bars and keys, the combination of a continuously rotating shaft,means for depressing said key-levers, a unit actuating member foroperating said means, including a driven slide and a keylever-drivingcross-bar, means set into operation upon the partial depression of a keyto effect coupling between said shaft and said actuating member to causesaid firstmentioned means to completethe depression of the correspondingkey-lever to swing the associated type-bar to typing position, and meansfor restoring said actuating member to normal position.

20. In a typewriting machine having type-bars, type-keys, anddepressible keylevers connected to said bars and keys, the combinationof a continuously rotating shaft, means for depressing said key-levers,a single actuating member for operating said means, electromagneticmeans set into operation upon partial depression of a key to effectcoupling between said shaft and said actuating member to cause saidfirst-mentioned means to complete the depression of the correspondingkey-lever to swing the associated type-bar to typing position, and meansfor restoring said actuating member to normal position.

21. In a typewriting machine having type-bars, type-keys, anddepressiblekeylevers connected to said bars and keys, the combination ofa continuously rotating shaft, means for depressing said key-levers, asingle actuating member for operating said means, electromagnetic meansset into operation upon partial depression of a key to effect couplingbetween said shaft and said actuating member, to cause saidfirstmentioned means to complete the depression of the correspondingkey-lever to swing the associated type-bar to typing position, means forrendering said electromagnetic means inoperative, and means forrestoring said actuating member to normal position.

22. In a typewriting machine having type-bars, type-keys, anddepressible keylevers connected to said bars and keys, the combinationof a key-lever-actuating memher, an electromagnet including acylindrical core spaced from said actuating member, means for rotatingsaid core, a switch operable upon partial depression of a key to closean electric circuit exciting said electromagnet to attract the actuatingmember to said core, and means connected to the key-levers and placed inthe path of the actuating member upon partial depression of a key, tocause complete depression of the corresponding key-lever to swing theassociated typebar to typing position.

23. In a typewriting machine having type-bars, type-keys, anddepressible keylevers connected to said bars and keys, the combinationof a key-lever-actuating member, an electromagnet including acylindrical core spaced from said actuating member, means for rotatingsaid core, a switch operable upon partial depression of a key to closean electric circuit exciting said electromagnet to attract the actuatingmember to said core, means connected to the key-levers and placed in thepath of the actuating member to cause complete depression of thepartially-depressed key-lever to swing the associated type-bar to typingposition, and means for returning said actuating member to normalposition, including means rendered operative by the movement of saidactuating member by said core to break the exciting electric circuit to.release the actuating member from said core.

24. In a typewriting machine having type-bars, type-keys, anddepressible keylevers connected to said bars and keys, the combinationof a key-lever-actuating member including an armature, an electromagnetincluding a cylindrical core spaced from said actuating armature, meansfor rotating said core, a switch operable upon partial depression of akey to close an electric circuit to excite said electromagnet andattract the actuating armature to said core, means connected to thekey-levers and placed in the path of the actuating member to causecomplete depression of the partially-depressed key-lever to swing theassociated type-bar to typing position, and means for returning saidactuating member to normal position, including means forshort-circuiting the exciting current through the core upon contact ofthe latter with the actuating armature, and for shunting the switch uponinitial movement of said armature by said rotating core, and meansrendered operative upon further movement of said armature to break theelectric contact between said armature and said core.

25. In a key-operated machine, the combination with a depressible key,of means operable upon partial depression of said key to complete thedepression thereof, said means including an instrumentality actuatedupon depression of said key, a continuously rotating shaft, an excitablecoil for magnetizing the shaft, an actuating member engageable with saidinstrumentality, and means operable upon partial depression of the keytoexcite the coil and establish an electro-magnetic field for saidrotating shaft to couple said actuating member and cause the actuatingmember to complete the movement of said instrumentality and itsassociated key.

26. In a key-operated machine, the combination with a depressible key,of means operable upon partial depression of the key to complete thedepression thereof, said means including an instrumentality actuatedupon depression of said key, a continuously rotating shaft, an excitablecoil for magnetizing the shaft, a movable slide, a pawl connected tosaid instrumentality and movable upon partial depression of the key intothe path of the slide, a normally open coil exciting circuit, a switchoperable upon partial depression of said key to close said circuit toexcite the coil and establish an electromagnetic field for the shafteffective to attract and couple said slide to said shaft, and therebycomplete the movement of said instrumentality and its associated keythrough engagement of the slide with said pawl, and means for returningthe slide to normal position.

bination with a depressible key, of means operable upon partialdepression of the key to complete the depression thereof, said meansincluding an instrumentality actuated upon depression of said key,acontinuously rotating shaft, an excitable coil for magnetizing theshaft, a movable slide, a pawl connected to said instrumentality andmovable upon partial depression of the key into the path of the slide, anormally open coil exciting circuit, a switch operable upon partialdepression of said key to close said circuit to establish anelectromagnetic field for the rotating shaft effective to attract andcouple said slide to said shaft, and thereby complete the movement ofsaid instrumentality and its associated key through engagement of theslide with said pawl, means operable by the movement of the slide forshunting the coil exciting circuit to cut out the switch, withoutdemagnetizing the coil, means movable with the slide for opening thecoil exciting circuit to demagnetize the coil, and means for returningthe slide to normal position.

28. The combination with a key-operated machine, an auxiliarykeyboard'having keys arranged to overlie and contact the keys of themachine, means for limiting the depression of the keys of said auxiliarykeyboard to substantially less than the stroke of the keys of themachine, and power means for automatically completing the depressions ofthe keys of the machine.

29. In a key-operated machine having keys and key-levers actuatedthereby, the combination with a key-driving member for each keyincluding a pawl moved by the key into the path of a driven member uponpartial depression of the key, and power-driven means set in motion bythe partial depression of said key to drive said member to complete thedepression of the key, of manually-operated means for moving said memberat will beyond the range of movement of said pawls to permit the manualoperation of the machine wholly by the keys.

30. In a typewriting machine, the combination with a system oftype-actions, each including a type-bar, of key-controlledelectromagnetic means for operating any typeaction, said operating meansincluding a reciprocatory common actuator and a revolving cylindricaldevice against which the common actuator may be magnetically drawn andheld with force sufficient to enable the cylindrical device to drive theactuator in one direction, together with the selected type-bar, by meansof friction between the cylindrical device and the actuator; and meansfor returning the actuator to normal position.

31. In a typewriting machine, the combination with a system oftype-actions, each including a type-bar, of key-controlledelectromagnetic means for operating any typeaction, said operating meansincluding a reciprocatory common actuator and a revolving cylindricaldevice against which the common actuator may be magnetically drawn andheld with force sufficient to enable the cylindrical device to drive theactuator in one direction, together with the selected type-bar, by meansof friction between the cylindrical device and the actuator; and meansbrought into action by the actuator at the conclusion of the printingstroke, for automatically terminating the driving of said actuator bysaid cylindrical device.

32. In a typewriting machine, the combination with a system oftype-actions, each including a type-bar, of key-controlledelectromagnetic means for operating any typeaction, said operating meansincluding a reciprocatory common actuator and a revolving cylindricaldevice against which the common actuator may be magnetically drawn andheld with force sufficient to enable the cylindrical device to drive theactuator in one direction, together with the selected type-bar, by meansof friction between the cylindrical device and the actuator, meansbrought into action by said actuator when driven by said cylindricaldevice, to automatically effect demagnetization of said electromagneticmeans, thereby to release the operated actuator, and means to return theactuator to normal position independently of the cylindrical device.

33. In a typewriting machine, the combination with a system oftype-actions, each including a type-bar, of a reciprocatory armatureforming a driver universal to all the type-actions, and key-controlledelectromagnetic means for operating the driver, said operating meansincluding a revolving cylindrical device against which the armature ismagnetically drawn and held with sufficient friction to enablethecylindrical device to drive the armature together with the selectedtype-bar.

34. In a typewriting machine, the combi nation with a type-bar and akey, of electromagnetic means foroperating said type-bar, including aconstantly-revolving magnetizable device, a reciprocatory actuator inthe form of an armature, normally separated by a gap from said revolvingdevice, means controlled by said key to magnetize said revolving deviceand thereby cause said armature to close said gap and to be magneticallyheld against the revolving device with force suflicient to enable thelatter to drive the armature and type-bar by means of friction; meansbeing provided for terminating the control of the revolving device overthe armature and type-bar, and means to return the armature and type-barto normal positions.

35. In a key-controlled typewriting machine having a power-driven shaftand a typeaction to be driven by the shaft, including a type-bar; anactuator, a member operated

